pardes - asks /pager for its +Pager and reads the serial on the same open: another client's exec meanwhile can never take the text into its pane

pardes - wrote `pager <dir>` to /ctl, then read /exec on a fresh open,
which answers the session's last answer: a client that exec'd in
between had its pane overwritten by the paged text. /pager takes the
directory and answers the +Pager's serial on the open that wrote it,
as /pane/new answers its own open; the ctl verb is gone. Client.ask
writes and reads on one open. The README's look recipe reads its
answer on its own open too.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 5 insertions, 4 deletions

diff --git a/src/main.zig b/src/main.zig
index 1075b596..6c46b22c 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -101,7 +101,7 @@ const help_text =
 ;
 
 /// `pardes -` inside a session: `text` into the directory's one +Pager
-/// (root ctl `pager <dir>`, refilled when it is there), written into its
+/// (/pager, refilled when it is there), written into its
 /// body through one open, as one undo step, and left clean. A text
 /// the session would not take is never lost: it goes to stderr, with why,
 /// and the exit is 1.
@@ -125,9 +125,10 @@ fn pageInto(io: std.Io, gpa: std.mem.Allocator, dial: []const u8, text: []const
         if (c < ' ' or c == 0x7f) break false;
     } else true;
     var line_buf: [4200]u8 = undefined;
-    const ctl_line = std.fmt.bufPrint(&line_buf, "pager {s}\n", .{if (plain) cwd else ""}) catch "pager\n";
-    ninep_io.Client.write(gpa, dial, "/ctl", ctl_line) catch |err| Fail.with(io, text, "no +Pager pane", err);
-    const answer = ninep_io.Client.read(gpa, dial, "/exec", "/exec") catch |err| Fail.with(io, text, "no +Pager pane", err);
+    const dir_line = std.fmt.bufPrint(&line_buf, "{s}\n", .{if (plain) cwd else ""}) catch "\n";
+    // Its serial read back on the open that asked: another client's exec
+    // meanwhile can never send this text into that client's pane.
+    const answer = ninep_io.Client.ask(gpa, dial, "/pager", dir_line) catch |err| Fail.with(io, text, "no +Pager pane", err);
     const serial = std.fmt.parseInt(u32, std.mem.trim(u8, answer, " \n"), 10) catch |err| Fail.with(io, text, "no +Pager pane", err);
     // The whole text through one open of the body (truncated once, then
     // written at rising offsets): one undo step, and every byte of it.